Question

A concave mirror of focal length 15 cm forms an image for an object placed at a distance of 20 cm from the mirror. find the image distance and hence its nature of image.
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Answer 1

Answer:

Explanation:

Here,                   f = -15 cm

                           u = -20 cm

        Applying mirror formula, we get

                           $\frac{1}{v}$  +  $\frac{1}{u}$ = $\frac{1}{f}$

        Putting given values:

                           $\frac{1}{v}$ - $\frac{1}{20}$ = $\frac{-1}{15}$

 ⇒                      v = -60 cm  

Also,                   magnification = $\frac{-v}{u}$ = $\frac{-60}{15}$ = -4

  ⇒    Image is inverted, real and magnified.